The objectives of this research project are to evaluate the hormonal regulation and relative significance of the adenylyl cyclase and protein kinase enzyme systems as early and integral parts of the molecular events which characterize gonadotrophin action in ovarian follicles and corpora lutea. Emphasis is placed upon the activity of these enzyme systems, as they are effected by different gonadotrophic hormones, in specific ovarian tissues throughout the reproductive cycle. When possible, correlations are made between the changes in activity of these enzymes and known physiological parameters of the reproductive cycle.